When Herp and Derp turned Doc McStuffins into Derp McDonuts, Derp burned the Big Book of Boo-Boos by using a flamethrower. Eventually, the whole world was set on fire, coinciding with the theme song, We Are Young, because one line says "So we'll set the world on fire" that is, if the world was the Big Book of Boo-Boos, that was already done. Yaaay.